this may describe the problem better
i dont have a multilib gcc to build a multilib glibc
thats why i need a pre-built miltilib glibc package to build a multilib gcc
the only one available is glibc-2.9

thats right it is,
and it does compile when not using multilib
i do have glibc-2.10 installed with out the multilib use flag
i need glibc-2.10 with mutilib
it not can or cant i compile glibc 2.10
its i cant installed the multilib glibc 2.10 hence the need for a binary multilib glibc-2.10

I managed to fix it by doing the following
I used a stage3 2008 and chroot to it
install the biarch binary glic2.9
compile basic gcc4.3.4 (this is where i always got stuck before)
compile glibc2.10
compile gcc4.3.4 with all the features I need

I decided to compile a basic gcc first because I thought some extra feature might have been causing the problem, I don't know if the is necessary
I now have the latest stable glibc and gcc in biarch
I dont know why it didnt work on my current machine, or a slightly older copy with glibc2.9